What these "China no socialist" ultras don't have is lack of conceptual understanding of what socialism is. The way they think is brilliantly described by Gabriel Rockhill in his Understanding Siege Socialism appearance, where he actually quoted Mao on this topic. In essence - ultras only have sensory understanding of what socialism should be, but not conceptual - let alone doing any praxis. They don't have a good grasp of dialectical materialism, they see socialism as "being this and that and that" - a set of characteristics that are present (or absent) in a given society.

Conceptual understanding of socialism is the realization that socialism (and communism) is first and foremost a long, painful, tedious and prudently planned contradictory process of consciously building towards a certain type of socio-economic order. It concedes that building socialism, whatever form it initially takes, means that a new society is born OUT OF capitalism and under tremendous imperialist pressure. It does not, however, preclude using different tactics (when appropriate) which may seem to contradict the overall goal or strategy.

No one in their right mind would say the USSR was not socialist, even though the NEP certainly allowed a wide range of private economic activity. Oh, by the way - it never went away fully because for that you have to develop productive forces to a colossal degree. On the other hand, the USSR did have a powerful planned/socialized sector by the time Khrushchev was in power, yet his right deviations and revisionism were obvious to many.

Perhaps it reflects their weak theoretical grounding, perhaps something else (ahem fed ahem). BTW the "global proletariat must rise up" is a big red flag imo (no pun intended). Even fucking capitalists admit China is not capitalist...